U.S. President Barack Obama has presented the Medal of Honor to an Army Ranger who protected fellow troops from a grenade attack in Afghanistan.

Presenting the medal at the White House Tuesday, President Obama called Sergeant First Class Leroy Petry an "extraordinary" American soldier. He quoted a fellow soldier who said Petry shows that true heroes still exist.

Petry is the second living person to receive the Medal of Honor for actions in Iraq or Afghanistan. He lost his right hand when he threw an exploding grenade away from two of his fellow soldiers during combat in Afghanistan in May 2008.

With his prosthetic hand, U.S. Army Sergeant First Class Leroy Arthur Petry applauds fellow soldiers during a ceremony in which he was presented with the Medal of Honor by U.S. President Barack Obama at the White House, July 12, 2011

Mr. Obama described Petry's action as a "selfless act" that saved his fellow troops. The president said Tuesday's ceremony was to honor what he called Petry's "singular act of gallantry," and also to pay tribute to a generation that he said has borne the burden of the nation's security during a decade of war.

Speaking after the ceremony, Petry said to be singled out is "very humbling." The 31-year-old said he considers all service members to be heroes. He said they sacrifice every day and deserve continued support and recognition.

Since enlisting in the Army in 1999, Petry has been deployed twice to Iraq and six times to Afghanistan. The married father of four now works as a liaison officer at Fort Benning in Georgia and helps wounded service members and their families.

A robotic prosthetic hand has helped him overcome his injury. Petry told the Army News Service that it "feels great" to shake people's hands.

Petry is the 9th service member to receive the Medal of Honor for actions in the wars in Iraq and Afghanistan. The only other living soldier to receive the honor for those conflicts was Army Staff Sergeant Salvatore Giunta, who was cited last year for heroism in Afghanistan.

The Medal of Honor is the nation's highest military decoration.

U.S. Army Rangers are elite soldiers who are trained to parachute into combat, can operate in deserts or swamps and have specialized skills needed to fight in mountains.